After some good performances for Livingston during the 2007–08 season, Dorrans was approached by West Bromwich Albion manager Tony Mowbray. In January 2008, Dorrans agreed to join West Brom at the end of the season for £200,000.[5] At the end of the 2007–08 season, Dorrans won the Scottish First Division Players' Player of the Year award.[6] In July his move to Albion was completed, but for an initial £100,000, which could possibly rise to £150,000 depending on appearances.[7]

He made his debut in the English Premier League for West Bromwich Albion on 21 December 2008, coming on as a second-half substitute against Manchester City.[8] He was involved in Albion's first goal and won praise from Tony Mowbray after the game.[8] Towards the end of the 2008–09 season, Dorrans signed an extended contract with West Brom.[9] On 15 May, West Brom confirmed that Dorrans would be out for the rest of the season with a broken metatarsal bone.

He scored his first goal for West Brom in a League Cup tie at Bury on 11 August 2009. The 2009–10 season saw Dorrans break into the West Brom team and his performances led to reported interest from several Premier League clubs. On 4 January 2010, Dorrans signed a new three-and-a-half-year deal at the Baggies.[10] On 11 February the same year it was rumoured that Manchester City were ready to make a bid for Dorrans believed to be around £6 million.[11] He scored a 30-yard free kick against Preston North End on 21 March.[12] Dorrans was then named PFA fans' Championship player of the month for March 2010, following his impressive performances.[13]

In The Guardian on 20 March 2010, he was described as, "Composed, creative, combative and consistent, Dorrans is easily the best all-round midfielder seen at West Brom since Bryan Robson."[4] In April 2010 West Brom rejected an offer of £4 million from West Ham United for Dorrans, and a further £5 million bid on 8 July 2010.[14] It was during this period that it was disclosed that former Livingston owner Angelo Massone had waived the financially stricken club's right to 20% of Dorrans' next transfer fee in return for £50,000. It was speculated that the windfall from Dorrans' potential transfer could have solved their financial problems.[15] On 19 July 2010, Dorrans signed a new four-year deal with West Brom.[16]

Dorrans was made available for transfer by West Brom in January 2013, after he was left out of a matchday squad.[17] He had a "difficult start" to the 2013–14 season, during which he made 16 appearances.[18] Despite this, he played more under new Head Coach Pepe Mel, leading to Dorrans signing a three-year contract with West Brom in July 2014.[18]

In February 2015, Dorrans joined Norwich City on loan for a month,[19] which was later extended until the end of the 2014–15 season.[20] The move was made permanent on 27 May 2015, just a few days after Dorrans helped the side win promotion to the Premier League, via the Playoff Final.[21]

On 6 July 2017, Dorrans moved from Norwich City to Rangers on a three-year contract for an undisclosed fee, reported to be around £1.3 million. He made his league debut for Rangers on 6 August 2017 and scored both goals in a 2–1 win over Motherwell.

On 7 September 2009 Dorrans was called up for the first time for the senior squad to play the Netherlands in a crucial World cup qualifier. On 10 October 2009 he made his full Scotland debut in a friendly against Japan. Dorrans made his home debut for Scotland on 3 March 2010 in the 1–0 victory over the Czech Republic, earning the sponsors man of the match award for his efforts.

Dorrans has not often been picked for Scotland squads under the management of Gordon Strachan because they agreed he would not be selected if he was unlikely to play.[23] They reached this arrangement due to Dorrans suffering from personal problems, as his son died at birth and his daughter contracted meningitis.[24] Dorrans was recalled to the squad in October 2015, when other midfielders were unavailable.[25]